NISCAIR Online Periodicals Repository Collection: IJBT Vol.07(4) [October 2008]

Development of synthetic seeds involving androgenic and pro-embryos in elite indica rice

Title: Development of synthetic seeds involving androgenic and pro-embryos in elite indica rice

Authors: Roy, Bidhan; Mandal, Asit B

Abstract: Synthetic seeds were produced from anther-derived mass-multiplied embryos and pro-embryos of rice (Oryza sativa L.) var. IR 72. A high dose (4-6 mg L⁻¹) of BAP was found to produce a large number of dormant embryos, pro-embryos and embryo-like structures in about 45 d. These were encapsulated in sodium alginate (2.5% w/v) matrix. Germination and plantlet regeneration capacity of the encapsulated seeds were tested by culturing them on MS fortified with different combinations and concentrations of BAP, Kn and NAA. The result indicated that BAP in combination with lower concentrations of NAA increased germination of beaded embryos over control (MS without hormones). High percent of germination (55-87.5%) was observed when MS was supplemented with BAP and lower concentration of NAA; whereas, addition of Kn in MS reduced the germination percentage. The germination of unbeaded pro-embryos was 92.5% on MS basal medium. The reduced rate of germination of artificial seeds may be attributed to the damage incurred while separating the embryos from clusters and/or owing to adverse effects of chemicals used for encapsulation. Moderate germination (40.0%) was seen on sterile sand. Synthetic seeds may be used for in vitro propagation as well as genetic transformation experiments, especially involving biolistics.

Page(s): 515-519

Genetic variability among sheep breeds by random amplified polymorphic DNA-PCR

Title: Genetic variability among sheep breeds by random amplified polymorphic DNA-PCR

Authors: Kumar, S; Kolte, A P; Yadav, B R; Kumar, Sushil; Arora, A L; Singh, V K

Abstract: Random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) was employed to assess the genetic variability and phylogenetic relationship among six breeds of sheep, viz., Malpura, Kheri, Chokla, Garole and two crossbreds Avikalin and Bharat Merino. Twenty-four individuals from each breed/crossbred were selected randomly. Initially, 40 primers were screened, of which 16 were found polymorphic and utilized for estimation of genetic variability and phylogenetic relationship among the breeds. The genetic distance was found highest between Malpura and Garole (D=0.1428), and the lowest (D=0.0612) between Avikalin and Chokla. However, the genetic identity was observed highest (I = 0.9406) between Avikalin and Chokla and the lowest (I = 0.8669) between Malpura and Garole. The Kheri sheep was found close with Chokla (D=0.0741), followed by Malpura sheep (D=0.0902) based on genetic distance. The phylogenetic tree also showed that Avikalin and Chokla are more close, whereas Malpura and Garole are distant to each other. The present study suggested that RAPD-PCR can be used successfully for analyzing genetic variation and phylogenetic relationship among breeds of sheep.

Page(s): 482-486

The PCR amplification, sequencing and computer-aided analysis of ovine S1-casein gene promoter

Title: The PCR amplification, sequencing and computer-aided analysis of ovine S1-casein gene promoter

Authors: Bhure, S K; Sharma, B

Abstract: The paper reports 5'-flanking sequences of ovine S1-CSNGP (casein gene promoter) of 2185 bp. It has shown many deletions, substitutions and a 12 bp addition compared to bovine sequence. The comparative study showed 2136 bp of 5'-flanking region and 49 bp exon I sequence. The exon I sequence contained two ribosomal binding sites. The computational analysis showed presence of core promoter elements, viz., TATA box, CAAT box and initiator sequence. However, no typical GC box was found. Of five known mammary gland specific sequences, three sequences, viz., milk box, Groenen structure and Yu Lee 6, were found. The 220 bp Groenen structure contained other milk protein gene specific sequences (MGF, MPBF, Yu Lee 2, 4 and 5, and Oka box C) and hormone responsive elements (PRE, PRL-RE). Other HREs (GRE, CRE, GHRE and IRE) and ubiquitous transcription factor binding sites were also present. These milk protein gene specific regulatory sequences and HREs are responsible for tissue specific and multi-hormone regulation of the ovine S1-CSNG.

Page(s): 478-481

Cloning and expression of FMDV-VP1 immunoreactive peptide in trivalent form and its application as immunogen

Title: Cloning and expression of FMDV-VP1 immunoreactive peptide in trivalent form and its application as immunogen

Authors: Nagarajan, G; Kumar, C Ashok; Dechamma, H J; Reddy, G R; Ganesh, K; Suryanarayana, V V S

Abstract: A search for alternatives to conventional inactivated virus vaccine for FMD with an aim to control and eradicate the disease globally, is a continuous process till a promising one is identified. Development of such vaccines underlines necessity of avoiding the use of active virus, and to have broader antigenic coverage so as to make them suitable even for disease free countries. Subunit or peptide vaccines have been shown to elicit neutralizing antibody response. However, the titres are low as compared to sera from animals vaccinated with conventional vaccine and fail to protect animals against virus challenge. This is probably due to the inclusion of only limited epitopes. Under such conditions, mixing heterologous epitopes from the various serotypes may be a better approach for elicitation of high titred antibody response. Keeping this in view, we have linked C-terminal half of VP1 carrying two B cell and one T cell epitope of three FMDV serotypes (O, A and Asia 1), which are presently in use as vaccine strains in India. The linked polyvalent gene was expressed in Escherichia coli and the 59 kDa fusion protein was studied for its immunogenicity in guinea pigs in comparison with the specific epitopes of type ‘O’ produced as a similar fusion protein of 30 kDa. The trivalent protein showed better neutralizing antibody response, even with single booster injection, as compared to monovalent protein as observed in ELISA and SNT. These studies show future scope for the development of protein/DNA-based vaccine for FMD.

Page(s): 472-477